For thousands of years, people have relied on advertising to learn about new products and new opportunities on the market. From town criers and notices posted outside taverns, to radio spots and highway billboards, the concept of advertising has remained essentially the same: to promote the sale of a product or service. What has changed through the years is the volume of advertising messages presented to consumers and the number of products and services that are available.
Although part of the goal of advertising is to reach as many people as possible, the proliferation of advertisements has caused some people to find ways to avoid exposure to advertising content all together. Radio stations are switched over at the first indication of a commercial message, televisions are muted or fast-forwarded through commercials, and software is installed on computers to prevent advertisements from being received. In addition to avoiding advertising content related to goods in which the consumer has no interest, however, such measures also keep the consumer from learning about products and services that may be useful to the consumer.
Along with increases in the volume of advertisements, advances in technology have also affected how people communicate with each other. “Presence” is a term used to describe a technology that enables the user of a telecommunications network to convey his status, for example his ability and willingness to communicate, to a potential communication partner. For instance, the user of a mobile terminal such as a cellular telephone may publish her presence state to indicate that she is done with her work day and would like to go out for dinner. Potential communication partners in this example may be a group of the user's friends who have received the user's permission to view her presence data. As a result of the user's published presence status, she may receive messages from two of her friends indicating that they will be free for dinner in half an hour, and the user and her friends may arrange to meet at a particular restaurant at that time. The user may update her presence data as often or as infrequently as she prefers and may include as much or as little information as she desires. In this way, each published presence state provides a picture of the needs and concerns of the user at a particular point in time.